Let-off mechanism for looms.



No. 807,721. PATENTED DEC. 19, 1905. T. A. B. CARVER. LET-OFF MECHANISMFOR LOOMS.

APPLICATION FILED JAN.13, 1905.

THOMAS A. B. CARVER, OF GLASGOW, SCOTLAND.

LET-OFF MECHANISM FOR LOOMS.

Specification of Letters Patent.

Patented Dec. 19, 1905.

Application filed January 13,1905. Serial No. 240,935.

To a whom it may concern:

Be it known that I, THOMAS A. B. CAR ER, a subject of the Kin of GreatBritain, residing at Glasgow, Scot and, have invented new and usefulImprovements inLet-Off Mechanism for Looms, of which the following is aspecification.

This invention relates to let-off mechanism for looms, the object of theinvention being to provide a simple mechanism for letting off the warpfrom the beam, so that a predetermined tension in the warp is uniformlymaintained to assure the proper weaving of a fabric.

My loom involves, in connection with a warp-beam and a whip-roll, whichmay be of the usual character, an electric circuit, including afeedcontrolling device for said warp-beam, and circuit-controlling meansautomatically operable when the tension of the warp exceeds a certainpoint, whereby, as will hereinafter appear, the warp-roll can be sooperated as to relieve the excessiveten- SlOIl.

In the drawings accompanying and forming a part of this specification Iillustrate an advantageous organization which can be very well employedfor maintaining a uniform degree of tension of the warp, and I willdescribe in detail hereinafter the said organization.

Referring to the drawings, Figure 1 is a side elevation of part of aloom involving my invention. shown in the preceding figure.

Like characters refer to like parts throughout the views.

In the drawings I have represented by the numeral 2 the framework of aloom, upon which is mounted the main shaft 3, the warpbeam 4, and thewhip-roll 5. These parts may be of the usual or ordinary construction.The warp passes from the warp-beam over the whip-roll 5, which, as willbe understood, is mounted for free rocking motion upon the framing. Thewhip-roll is represented as having lateral trunnions or gudgeons, as 6,only one of which is illustrated and which extends freely through andbeyond a hub on the framework of the loom. (See Fig. 2.)

, Upon the trunnion 6 is a lever 7, which to distinguish it from anotherlever hereinafter described may be termed a primary lever. In thepresent instance the primary lever 7 is rigidly united with the trunnion6, so as Fig. 2 is a rear view of the parts 7 to constitute, in eflect,arigid part of the whiproll. This relation may be secured in any desiredwayfor example, by a set-screw extending through the hub of the lever 7at the junction of its two arms and bearing upon said trunnion. It willbe seen that the lever 7 is of substantially angular form.

Loosely carried by the trunnion 6 is a secondary lever 8, having anenlarged or widened head of bifurcated form, the branches of which havescrews 9 and 10 passing through sleeves thereon and adapted to be heldin longitudinally-adjusted relation by means of checknuts. The screw 9,as will hereinafter appear, constitutes part of an electric circuit,including a feed-controlling device for the Warp-beam. Between whatmight be considered the points or opposite inner ends of the two screws9 and 10 the upper end of the short arm or branch of the primary lever 7is arranged for back-and-forth motion, the inner face of said short armhaving an electric contact member 11. The screw 9 and the contact member11 are insulated from the parts which directly carry them.

From the screw 9 to one terminal of the electric motor 12 a conductor,as 13, extends, a conductor, as 14, extending from the opposite terminalor pole of the motor to the contact 11, being intersected by agenerator, as 14', which may be an electric battery or some equivalentmeans.

A pitman, as 15, is driven continuously from the main shaft in somesuitable manner, as by means of an eccentric 16 thereon, said pitmanbeing adjustably connected to the lower branch of the secondary lever 8,the adjustable connection being shown as the familiar pin-and-slot one.To a projection or offset (represented as being at the extreme lower endof the lever 8) is connected one end of a sprin 16, the opposite end ofsaid spring being a justably connected to the longer and arcuate arm ofthe lever 7. It

will be understood that the tension of the spring 16 acts against thatof the warp.

The action of the organization is as follows: So long as the tension ofthe warp is course moving therewith, so as to carry the contact 11against the screw 9, thereby closing the circuit involving the electricmotor 12. The shaft of the motor is illustrated as connected byworm-gearing (denoted in a general way by 17) with the warp-beam. When,therefore, the circuit is closed, the motor will be operated so as toturn the beam 4 in a direction to let off the warp, and consequentlyreduce the tension. When the tension of the warp is reduced, the spring16 will at once operate upon the lever 7 to return said lever andwhip-roll to their original positions, during which motion the contact11 is carried away from the screw 9 to break the motor-circuit, andtherefore stop the motor, and the consequent motion of the warpbeam.This relation will be maintained until the tension in the Warp becomessufficient to effect the closing, through the intervention of the agentsdescribed, of the motor-circuit, when the motor will again be 0 eratedto relieve the excessive tension of t e warp.

The lever 8, which carries at its head the two screws 9 and 10, will beoperated from the main shaft in such a way as to preserve a uniformtension in the warp during the cycle of the loomthat is to say, whilethe tension in the warp is being increased by the movement of theheddles or reeds the lever 8 is moved in a direction to permit the lever7, and therefore the whip-roll 5, to rock toward the heddles, and viceversa.

Although I prefer to operate the lever 8 in the manner described, I mayin some instances accomplish the same results without such movement bymounting the two screws 9 and 10 and connecting the spring 16 with theframe of the machine.

Although I have described the beam as being revolved by a motor when thetension in the warp becomes greater than that previously determinedupon, I may use other means for causing the closing or opening of anelectric circuit to govern the action of the beam. For instance, thecircuit might include a solenoid or electromagnet, the attraction'set upin which may release a bandbrake of any well-known form, or I may passthe current through an electromagnetic clutch of any well-known formgeared to the warp-beam in such a way that the breakageof the currentwill release the clutch and allow the beam to revolve. In the lattercase the screw 10 would be included in the circuit instead of the screw9, for the reason that I have'described my preferred means for securingthe novel results set forth and have suggested certain othermodifications. Other ways of obtaining the functions desired can bereadily made.

Instead of employing a spring, as 16, hereinbefore described, I mightuse its equivalent-a weight suspended from the long arm of the lever 7.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. In a let-off mechanism for looms, the combination of a warp-beam, awhip-roll, an

electric circuit including a feed-controlling device for said warp-beam,and means for controlling the circuit and automatically operable, whenthe pressure on the warp eX- ceeds a certain point.

2. In a let-oil mechanism for looms, the combination of a warpbeam, awhip-roll, an electric circuit including a feed-controlling device forsaid warp-beam, and circuit-controlling means operative with thewhip-roll.

3. In a let-ofi' mechanism for looms the combination of a warp-beam, awhip-roll, an electric circuit, including a motor, operatively connectedwith the warp-beam, and circuit-controlling means operative with thewhip-roll.

4. In a let-off mechanism for looms, the combination of a warp-beam, awhip-roll, an electric circuit, including a feed-controlling device, forsaid warp-beam, circuit-control ling means, automatically operable whenthe tension of the warp exceeds a certain point, and tensioning meansacting against the whip-roll in opposition to the tension of the warpapplied to said roll.

5. In a let-off mechanism for looms, the combination of a warp-beam, awhip-roll, an

electric circuit, including a feed-controlling device, for saidwarp-beam, means for closing the circuit when the tension of the warpexceeds a certain point, and a spring, operatively associated with thewhip-roll and serving to apply a tension to said roll in op position tothat of the warp.

6. In a let-off mechanism for looms, the combination of a warp-beam, awhip-roll, an electric circuit, including a feed-controlling device, forsaid warp-beam, a lever rigidly associated with and movable with thewhiproll, said lever having a circuit-closin device, and a springconnected with the ever and arranged to apply its tension to thewhip-roll in opposition to that of the warp.

7. In a let-off mechanism for looms, the combination of a war -beam, awhip-roll, an electric circuit, inclu ing a feed-controlling device, forsaid warp-beam, a lever rigidly associated with the whip-roll and havinga circuit-closing device, a second lever movable independently of thefirst lever and having a part of said circuit arranged for contact bysaid circuit-closer, means for vibrating the second lever from the mainshaft of the loom,

and tensioning means acting against the first lever, and thereby thewhip-roll, in opposition to the tension of the warp.

8. In a let-off mechanism for looms, the combination of a warp-beam, awhip-roll, an electric circuit, including a feed-controlling device, forsaid warp-beam, a lever rigidly associated with the whip-roll and havinga circuit-closing device, a second lever provided with screws, betweenwhich said circuit-closing device is arranged to operate, one of thescrews constituting part of said circuit, and said second lever beingmovable independently of the first lever, a spring connecting the twolevers and serving to apply a tension to the whip-roll in opposition tothat my hand in presence of two subscribing wit- 0 THOMAS A. B. CARVER.

Witnesses ARTHUR W. J OYOE, CLAUDE 0. BALL.

